Shades of Olympus
by Kirii
Summary: Fresh from the war against Luke and Kronos' Heartless, Percy is sent on a new journey. An older threat is awakening and Percy must unlock the Keyholes that hold the Olympians captive, while fighting this threat, searching for Annabeth, and trying not to throttle the mysterious boy from the Realm of Darkness. Yeah, no problem. [Kingdom Hearts AU; slow-building slash and femslash]
1. Chapter I

**Author's Note: ** So, this has been in the works for a couple of months. The idea struck me a while back and I finally just could not resist it anymore. This is probably one of the biggest fandom projects I've ever undertaken, but hopefully, I can pull it off! If you're on tumblr, check out the shades-of-olympus blog for art and extras for this AU.  
**Warnings: **This completely AU fic will ultimately have slash and femslash. Some dark-ish themes will be explored, and it may take me a long to time to complete this fic, as I'm still sorting out some details for later chapters.  
**Disclaimer: **I lay no claim to either series this fic is based on. I am not a representative of either Rick Riordan or Square-Enix. I am just a bored woman with lots of ideas.  
**Shout outs: **Much love to Cedarleaf for encouraging me and to everyone who's seen the art I've done for this and encouraged me to get this written!

**- Chapter One -  
**

It was too soon for Percy to start another journey. His last one had only just ended. The last war, against Kronos and his army of Heartless, had been hard on him and on the entire camp. One of their own, a Keyblade wielder by the name of Luke, had given into the darkness and joined Kronos, his Keyblade the instrument that allowed the Titan Heartless to gain advantage over the demigods of Camp Half-Blood. It was only through the combined efforts of Percy, another Keyblade wielder, and his best friends, Annabeth and Grover, that Kronos' attempts to take over Manhattan, the center of Western Civilization and the current home of the Greek gods, were thwarted.

Kronos' defeat had not been easy. The Titan Heartless had taken over Luke's body, using the demigod's Keyblade to its full potential to unlock Kingdom Hearts, the ultimate source of light. He'd wanted to use it to take over Olympus and he got very close. Percy and the possessed Luke had been fighting, so close to the heart of Olympus, when Percy had shattered Luke's Keyblade and Annabeth had taken advantage of the brief moment when Kronos was surprised to break through the Heartless' hold on Luke. Her cry of "You promised!" had pulled Luke free, if only long enough so he could sacrifice himself, to give Percy the chance to close the door to Kingdom Hearts and stop Kronos for good.

It was supposed to end there. Luke was dying, his body as shattered as the Keyblade he'd once wielded. Kronos had faded. Olympus was safe. Then, Luke had confessed a secret as he died, leaving both Percy and Annabeth shocked, confused, and speechless. Annabeth had not taken it well and the disappearing darkness surrounding them had caught her, sensing negativity in her heart and using it as a hold to pull her down. Percy and Grover had both tried to catch her, but the darkness had closed before they could reach her.

The darkness hadn't just swallowed Annabeth, though. When things had settled, Percy and Grover had found that the darkness had surrendered someone else. Where Annabeth had disappeared, it had left a dark-haired boy, a couple years younger than Percy. The boy had been unconscious, holding an iridescent black Keyblade in his hand. Percy and Grover hadn't had much choice, but to take him back to Camp Half-Blood with the others who had been helping them fight.

Chiron had taken the boy from Percy and told the son of Poseidon that the fight was not finished. There was still another journey ahead of him and this journey started right there in Camp Half-Blood. Holding the unconscious boy in his arms, the centaur nodded towards the hearth that burned in the middle of the cabin green. Percy stood before the hearth now, sensing the presence of a Keyhole that he'd never sensed there before. He summoned his Keyblade and took a step back. With a flick of his wrist, he used the Keyblade to open the lock.

The coals of the hearth flared to life, brilliant flames rising several feet into the air. Percy had to bring his arm up over his eyes after a couple moments because the light from the flames was just _too bright. _Only when the whiteness in the back of his eyelids faded did Percy dare to lower his arm and open his eyes. Whatever he'd been expecting to see before him, the small figure of a young girl was not it.

She looked no more than nine years old, small and slender, with brown hair that curled around her face and warm eyes, glowing the same red-orange as the coals had been before the flames had come to life. Standing no higher than Percy's stomach, the girl was about as unassuming as could be. She looked like any other little girl, except for her eyes, and that's what had Percy being cautious.

"Hello, Perseus Jackson," the girl told him, a smile forming on her lips.

Percy knew only three reasons why anyone used his full name; because he was in trouble, to taunt him, or because ancient gods liked using full names. He could pretty easily figure out that this girl wasn't angry with him or mocking him, so that only left the third option. He probably should be respectful and bow, but he was exhausted, physically and mentally strained from the fight against Luke and Kronos. A nod of his head and a soft 'hello' in return was about all he could bring himself to manage.

The girl seemed to notice his exhaustion and she reached out, taking his hand. Her hand was warm and the warmth from her light grip spread from his fingers, up his arm, and throughout his body. Percy felt an instant sense of rejuvenation, similar to how he did when the water restored his energy after a long day. Tension in his muscles eased and the injuries he'd received in the fight ceased their throbbing as the girl held his hand. He felt like a weight had been lifted off his shoulders and, considering he'd once held up the sky, that was saying something.

"Who are you?" he asked.

The girl looked up at him with her soft smile. "I am Hestia, the last of the Olympians and goddess of the home and hearth. I have been waiting to meet you, Percy."

Percy blinked at her. "You have?"

Hestia nodded. "I knew you'd be the one to unlock the cage holding me. Thank you." She gave his hand a gentle, appreciative squeeze before letting go. "However, I am not the only one who needs your help. The others are caged, too."

"The other Olympians?" Percy had noticed that the Olympians had not been around to help in the last battle against Kronos and he'd been wondering why. For gods whose very existence had been at stake with Olympus being attacked, they hadn't been around to defend their own home. If they'd been caged, locked within Keyholes, that would explain a lot.

"During the fight with Typhon, they were all captured, one by one," Hestia told Percy. "Kronos is not the only one who would take down Olympus. Gaea is awakening."

Percy had heard about Gaea before. Chiron had mentioned her once, when he'd first come to Camp Half-Blood, when he was new to the world of Greek gods and heroes. He didn't know much about her. Annabeth had always been the one with a wealth of knowledge, from who was who in the Greek pantheon to the how and why of architecture. He'd once watched _Jeopardy! _with her and spent most of the time just gaping at the daughter of Athena; if Annabeth ever got on the show, she'd probably shatter records.

"Let me guess," Percy said, after a long moment. "If the gods aren't freed, Gaea will wake up, and civilization as we know it will end?" At Hestia's solemn nod, he continued. "And you want me to go out there to free them. This is the journey Chiron told me about."

"Yes," Hestia nodded. "But it's not your journey alone. You will need help."

"Annabeth?" A pang of guilt shot through the son of Poseidon. He'd failed to save Annabeth, catch her as the darkness opened beneath her. If he'd just caught her hand, he could have pulled her back up. She'd fallen an hour ago, armed only with her dagger and a shield. Percy hoped that she would be alright, that she'd survive in the Realm of Darkness, and not let a painful realization cause her to lose herself.

"No." The answer from Hestia had Percy looking at the girl-goddess in shock. "Annabeth is on her own journey. She must walk through the Realm of Darkness alone."

"She's there because of me!" Percy protested. "She's not even supposed to be there! If Luke - !" He had to stop himself. Repeating what Luke had said would not help him argue with a goddess and, really, he couldn't bring himself to say it anyways. He didn't need it getting out. So he just heaved a sigh, hanging his head. "So, if it's not Annabeth, who's going to help?"

Hestia glanced past Percy towards the infirmary, where Chiron had headed with the unconscious boy from the Realm of Darkness. "That boy the Darkness exchanged for Annabeth," she answered. Her warm eyes softened, an unspoken sadness in them, as if she knew something about the younger boy that she didn't dare to voice. "This journey is his, as well. It may well be more _his_ journey than yours, in some respects. The two of you will need each other to succeed in this."

Percy couldn't help feeling some discontent, hearing that. He didn't know the boy. He didn't even know the boy's name. Hestia had said that the Darkness had exchanged the boy for Annabeth, which had a nagging voice in the back of Percy's mind suggesting that the boy couldn't be trusted; the Darkness had given him up, maybe as a trap. Darkness couldn't be trusted, so why should someone _from_ the Darkness be trusted?

"Nico is more than just someone from the Darkness," Hestia spoke up, interrupting that nagging voice, like she could hear it just as well as Percy could. "He is a Keybearer like yourself, walking the road to Dawn. He has fought for a long time, just as you have."

"Luke was a Keybearer, too," Percy pointed out. Luke's name left a harsh taste in his mouth, emotional wounds from the fight with the older Keybearer still fresh. "I trusted _him_. Look where that led."

"Luke strayed," Hestia said. "He walked the path of Darkness for a long time, but in the end, he found his way back to the Light. You saw it for yourself. The Darkness is not binding. There is always a Light to guide hearts _away_ from the Darkness." The goddess' eyes brightened, a fire in them much like the fire that she protected; the hearth of Olympus. If anyone knew about Light and guiding hearts, it was the goddess of the hearth, she who was honored even before Zeus. "Luke made his amends. Nico will make his own. All I ask is that you let him."

Percy gave a nod. He'd had arguments with gods before, but Hestia made it difficult to argue. Actually, arguing with Hestia was much like arguing with Annabeth; where Percy would try to refute, she would state simple, inarguable facts. It was clear that she knew what she was talking about, she was right, and Percy was being ridiculous. So he couldn't do anything more than give a nod and let her win. Percy wondered if Hestia did this with her brothers, the always arguing Big Three.

Whether she did or not, he wasn't going to ask. Instead, he focused on the journey she kept talking about. "So the kid and I are supposed to go out there and find where Gaea's locked away the other Olympians. How do we know where to go? Where do we start?"

"I only know where one other is locked away," Hestia told him. "My eldest brother, Hades, is locked away at the entrance of his realm. You know where that is."

"Los Angeles." Percy had been there once, with Annabeth and Grover, during his first quest. He remembered where the entrance was. He just hoped he wouldn't have to put up with old Crusty again.

"There's another entrance. Nico can lead you to it. Take that entrance, follow Nico through the Underworld to the Los Angeles entrance. It will take less time."

"How would Nico know where the entrance is?" Percy asked, arching a brow.

"Because I'm the son of Hades."

Percy turned to look over his shoulder. The very boy in question was standing behind him, looking exhausted, but able to stand on his own two feet. Chiron was not far behind, a stern look on his face, seeing as his patient had escaped his care. Nico didn't seem to want anything to do with being in the infirmary and, instead, was focused on Percy and Hestia.

"I didn't think Hades _had_ kids," Percy said.

"You're looking at one right now," Nico replied, coldly.

Percy gave a frown. Already, he was getting the feeling that he wasn't going to like this kid. Nico couldn't be much older than thirteen, maybe fourteen. His black hair was messy and his fringe was long enough that it nearly covered his eyes. Torn black clothes did little to hide how pale and thin he was, and, though he wasn't that tall, he held himself as though he were, alert and straight. Nico's general appearance alone made him stand out, made him seem like the kid to avoid. Percy had gone to school with kids like him and he didn't particularly like _them, _either.

And then there was Nico's _attitude_. For a younger teen, he had no problem throwing retorts back at Percy. Most kids his age would be a little intimidated by Percy, being older and a son of Poseidon. Nico acted a lot like his father; the one time that Percy had met the god of the Underworld, Hades had been dismissive, making it clear that he considered Percy beneath him. Nico did the same and it really grated on Percy's nerves.

"Excuse me for not immediately accepting your claim, Your Underworldness," Percy retorted, crossing his arms over his chest.

Nico shot him a glare and the two of them would probably have gotten into an out-right fight, had Hestia not intervened. Giving the two demigods a look that clearly said she would not put up with any fights, the goddess cleared her throat and produced a bundle of clothes for each of them. It was only as she handed him a bundle that Percy was even aware of how destroyed his clothes were from the fight against Kronos and Luke.

"I must return to Olympus," Hestia informed the two demigods. "My hearth must continue to burn. The flames there are the heart of Olympus. I will trust you, Percy and Nico, to rescue the other Olympians. My hope, and the hope of the rest of Olympus, rests on you. I wish the both of you all the luck I can give."

Percy thanked Hestia and Nico gave a silent nod. Both of them averted their eyes as Hestia left, returning to her true form to send herself back to Olympus. After she was gone, the two teens looked to each other.

"You should let Chiron take another look at you," Percy told Nico.

"I'm fine," Nico replied. He turned on his heel. "I'm going to go change. I'd suggest you do the same, then get whatever supplies you need."

"Who put you in charge?" Percy demanded, irritation rising within him from the younger boy's attitude. "I'm older."

Nico gave a laugh, bitter and mirthless. "Whatever. I'm still the one who knows where to go."

With that, Nico headed towards the infirmary to change, leaving Percy to grumble. Chiron watched the younger demigod for a moment and Percy could have sworn he saw the same unspoken sadness in the centaur's eyes as he'd seen in Hestia's. It made Percy wonder just who Nico was that both Hestia and Chiron seemed to empathize so much with the brat. Chiron clopped off before Percy could question him and, with a sigh, the son of Poseidon headed to his own cabin to change.

* * *

Getting into the Underworld, even with Nico there to show him where the other entrance was, had been a challenge. Heartless seemed bound and determined to stop them. Manhattan was still overrun with the monsters and Percy kept looking towards the part of the city where he knew his mother was. He could only hope that she was safe. Grover had promised to make sure that Sally and her husband, Paul, would be safe and even a handful of demigods had stayed back to stay with them, just to be on the safe side. Percy was grateful to them for it, knowing that more than one of them had already lost their mortal parents to these Heartless. It meant a lot to him that they'd help protect his mother.

In addition to the Heartless that kept leaping out of nowhere, when they actually got to the entrance of the Underworld – which was, to Percy's surprise, in the middle of Central Park; practically under his nose the whole time he'd lived in Manhattan – they'd found it locked. The lock itself was easy enough to open, with the two of them being Keybearers, but then Nico had told him that this particular door could only be opened with music.

Percy had been forced to whistle out a horribly off-key rendition of "Hotel California" that probably would have sent dogs running off howling if there'd been any within hearing distance. As bad as it had sounded, it had worked for the door, which Nico told him had been made by Orpheus. Percy had asked him how good of a musician Orpheus had to have been for his whistling to open the door, but Nico had just rolled his eyes and stepped into the entrance.

"You have no sense of humor, do you?" Percy asked.

"Shh!" Nico hissed back. "Do you _want _the Keres to find us?"

Percy grumbled again, still not liking Nico all that much. The kid didn't talk much, didn't so much as crack a smile. How long had Nico been in the Realm of Darkness that he'd become this hardened? Was Nico _really _on Hestia's "road to Dawn" or was he still stuck in the same Darkness that had let him go? What had happened that Nico had fallen into the Realm of Darkness in the first place?There were so many questions that Percy had about his reluctant companion, so many things that he wanted to know before he got much further into this journey with the kid. The problem was that Nico didn't seem intent on sharing.

There was almost no choice but to follow Nico in silence, through the Underworld. Any time Percy tried to strike up conversation, the younger demigod would tell him to shut up. It annoyed him to no end, pushed Percy to the limits of his patience, but he kept quiet for the most part. The only times they actually spoke was when Heartless appeared and they had to fight the creatures off, giving each other directions, giving warning when one of the Heartless was getting too close to them. It was hardly anything to get a feel for who this kid actually was, but at least Percy got a feel for how he fought.

It wasn't until they reached the fields of Asphodel that Percy actually became convinced that Nico was the son of Hades that he claimed to be. The moment they stepped into the fields, the spirits that had been so listless and sad when Percy had first visited the Underworld took one look at the younger demigod and all took a leap back, as though his very presence terrified them. It wasn't the black clothes, the dark eyes, or the wicked-looking Keyblade that Nico carried that frightened them; it was just that it was _him._ The spirits paid no attention to Percy at all.

The commotion brought the attention of an old acquaintance. The Fury that had once been Percy's pre-algebra teacher, Mrs. Dodds, flew over and landed in front of them. Shriveled and stooped, the creature grinned at Percy, clearly remembering him, then turned to Nico. Almost immediately, her grin faltered and she made a surprising gesture of respect, bowing her head to him. Nico just gave a nod.

"Alecto, we need to get to my father," Nico told her. "You know where he would be."

Alecto nodded. The other two Furies appeared behind her, dropping down to give the same respectful nod to Nico before one of them picked the younger boy up. Alecto moved forward to grab Percy, much to his protest. The last thing he wanted was to have to be carried by the same being that had once been trying to kill him. No way he trusted her, her sisters, or the strange boy they apparently took orders from.

"I can walk!" Percy protested.

"It's two miles to the other entrance from here," Nico pointed out, rolling his eyes. "By the time you walked there, I'll have freed my father and moved on to the next Keyhole."

The challenging tone in Nico's voice made Percy grit his teeth. Hestia said that the two of them would need each other to succeed in unlocking all the Keyholes and releasing the Olympians, but Nico was making it _really _hard to want to work together with him. The condescending attitude was almost worse than Clarisse's and the daughter of Ares wasn't exactly easy to be _worse than_ at anything. Percy glared at Nico, then let Alecto pick him up at last.

The Furies carried the two of them across the Underworld, their large wings making it easy to cross the two mile distance from Asphodel, past the Judging Pavilion, and to the edge of the Styx. This was where the Furies would leave them; they could not take the two demigods across the Styx. Only Charon could do that.

"Do you have any drachma?" Nico asked as the Furies flew off again after dropping them onto the ground.

Percy arched a brow at him. "What, you can't just order Charon to take us across like you did with the Weird Sisters?"

"The Erinyes," Nico corrected him. He rested on hand on his hip, tapping a finger against his hip, and wrinkling his nose. "And no, Charon doesn't take orders unless they're directly from my father. We have to pay to get across."

"But we're going the wrong way," Percy said. They weren't crossing the Styx to enter the Underworld; they were heading towards the entrance, not away from it.

"We still have to pay. I can talk him into taking us across, but he'll still demand payment."

Percy dug into his pocket for the handful of drachma he'd decided to bring along. Heartless sometimes dropped money when they were destroyed, so he'd pick up what was left behind. He'd never really understood why Heartless had money to begin with; maybe they picked it up because it was shiny. Whatever the reason, there were times that a Heartless was loaded with money, both mortal coins and drachma. He'd picked up the rare coin that Annabeth had studied for a moment and declared worthless, something she called _denarii_. Worthless or not, it went into the zipped pocket he kept most of his hoardings in.

He pulled out most of the drachma he had, hoping that Charon didn't recognize him and remember the last time he'd bribed his way across the Styx. Something told him that the ferryman had never gotten the raise Percy had off-handedly brought up with Hades the last time he'd been down here. He was pretty sure Charon didn't take disappointment too well and would hold it against him.

Nico summoned his Keyblade and shot off a burst of fire magic – Percy took note that Nico's fire was the green flames of Greek fire. The fire acted as a signal and it wasn't long before Charon's barge appeared through the dark mist that rose off the polluted black that was the Styx. The boat was empty of spirits, unlike the last time Percy had taken a ride across the Styx; apparently, Charon wasn't in a generous mood with the spirits in his waiting room. Maybe someone had changed the station on his radio again.

"You." It was hard to tell with Charon's head being in skull mode, but Percy was almost sure that the ferryman was glaring. At which one of them, he wasn't sure. Maybe both of them. "What do _you _want?"

"We want a ride across the Styx," Percy told him.

"I don't do go-backs." Charon used his pole as a prop, hands folded over the end and his chin resting on top of his hands. It probably wouldn't have looked so creepy if his face had flesh on it. "You're out of luck, godlings."

"Are you sure about that?" Percy asked as he flipped one of the golden drachma he had in his hand, letting it glint in the eerie light of the Underworld. Charon watched it flip in the air for a moment, clearly interested in the coin, but he made no move to snatch it.

Nico stepped forward, pulling out some of his own drachma. "There will be more once you take us across."

"Yeah, Green-Eyes over there tried that once," Charon told Nico, sounding bored. He leaned on his pole for a moment longer before straightening. "I'm only gonna take you guys across because _you _- " he used his pole to point to Nico, " - are the boss' kid. Full charge, of course. I don't do anything for free."

"Robbery," Percy muttered, earning himself a glare from both Nico and Charon.

"It's what you gotta pay for going the wrong way on a one-way road," Charon retorted.

Nico cut in before Percy could argue. "Deal. Take us across."

Percy ended up handing all of the drachma he had to the ferryman, as did Nico. Charon slipped the coins into a black pouch on his robe and let the two demigods onto the boat, then pushed off the shore. The boat ride was as silent as death – no pun intended, honestly. Neither Nico nor Charon were the talkative type and Percy didn't much feel like talking, when there was a sense of feeling dead around him. He couldn't even reach for Annabeth's hand this time, for the reassurance that he was still alive. Annabeth wasn't there to assure him of anything.

The ride seemed much longer than it had before. Percy assumed that it was because they were going against the current of the Styx. Charon was challenging the flow of the river, which made it difficult to get across again. As they got closer to the other shore, though, Percy could feel the sense of dread ebb, replaced by the sense that the living world wasn't far away. The entrance to the Underworld was ahead. Once they released Hades, Percy and Nico could leave the Underworld and head back to where it was easy to breath and the gloom of the realm of the dead was just a bad dream.

At least, that was the hope that was quickly being squashed by the fact that the boat had _stopped moving._

"Charon, what are you _doing_?" Nico demanded.

Percy turned in his seat just in time to see the ferryman throw his pole into the slew of broken belongings, crushed flowers, and ripped diplomas that polluted the Styx. Charon's face seemed to be caught between skeletal and flesh, divided in unequal parts. Like his face, his wardrobe seemed to be at war with itself, a bizarre mix of the Italian suit Percy remembered and the iconic Grim Reaper's robe.

"What is the meaning of this?!" Nico stood up, summoning his Keyblade and pointing it at Charon. "I said _take us across_!"

"For what purpose?" Charon asked, grinning a grotesque half-skeletal smile. "So you can release your old man and I can go back to meager pay and ungrateful spirits clogging up my lobby? You think I'd give up this suit for the second-hand monkey-suit I used to wear?" The ferryman laughed. "Not a chance! You two won't be getting across my river. Not alive, anyways."

Percy summoned his own Keyblade and stepped to stand beside Nico. The barge they were on rocked on the river, a dangerous arena for a fight, but they had little choice. It was either fight or die and Percy didn't dare even consider the latter an option, not when he had to find Annabeth and release the Olympians. He was not going to let them down.

"Nico, look," Percy told the younger teen, gesturing to Charon with his Keyblade. He could see a dark aura around the ferryman; an aura he'd seen before. In the last war, he'd seen the same aura around Ares. It was a sign of the Heartless' dark influence, of Kronos' manipulations. "He's being used."

"I can _see _that," Nico replied, dryly. He gripped his Keyblade tighter. "We'll have to break the hold on him if we're going to get across the Styx."

Charon gave a derisive snort. "The only way you're going to get across the Styx is when I throw you in!" He lunged towards them, skeletal hands reaching to attack. His fingers had lengthened into claws, perhaps a gift from the Heartless influence holding him. "I'll tear your hearts out and present them to my matron!"

Percy and Nico took the defensive, raising their Keyblades to block Charon and keep him from following through with his threat. Bone scraped against metal and the barge rocked hard from the movement. Percy shoved his weight forward, throwing Charon back, and, while Nico shot forward to go on the offense to distract the ferryman, concentrated on the dark, oily waters of the Styx. It was instinct for him to use water as a weapon, even water as unnatural to him as the Styx, and it wasn't until Nico shouted for him to stop that he realized that, maybe this time, his instincts were wrong.

The Styx pulled itself out of his influence and heaved, slamming into the barge. Percy, Nico, and Charon were all thrown overboard.

* * *

_**End note: **Yep, that's where I'm ending the chapter. I'm starting off with a bang. Please leave some feedback on this while I work on the next chapter!_


	2. Chapter II

**Author's Note: **Apologies for the wait on this; I had to figure a few things out before I could continue writing and then life, as it does, got in the way. Thanks for being patient with me! A note before you read, there are going to be some obvious deviations from canon, mainly concerning Nico's past. This is important to note, as there will be some mentions of Certain Events in his past that we'll be exploring this chapter.  
**Disclaimer:** I bet you $5 that if Riordan ever found out about the things I do with his characters, he'd smack me in the face. With a fish, maybe.  
**Shout-outs to: **Cedarleaf, Charlie, and Hazelle, for their help in figuring out details for this chapter and future key aspects of this fic! I couldn't do it without you guys! Love you!

**Chapter Two**

Percy knew that the Styx was dangerous. All of the Underworld rivers were bad news. At least, he thought, it wasn't the Lethe he was about to fall into; he could probably still pull himself out of the Styx with his memory intact. He and Nico didn't have time to deal with falling into rivers, though, especially when they had a quest to fulfill and a crazed ferryman of the dead to defeat. He had to do something keep them from landing in the dangerous waters of the Styx.

Despite the Styx's earlier rebellion, Percy put everything he had into forcing the river to obey and managed to get it to throw a rather large grandfather clock underneath Nico as the other boy fell. The son of Hades gave a grunt of pain as he hit the clock. He looked up just in time to see Percy hit the water.

"Percy!"

Falling into the Styx wasn't like falling into just any water. Percy had jumped into pools, fallen into the Mississippi River, dived into the Hudson River. Water had never hurt Percy before. He was the son of Poseidon; water was his ally. Apparently, the Styx had never gotten that particular memo. The polluted waters of the river of the dead burned Percy's skin, a scorching pain that seared through his entire being. He couldn't breathe in this water, as he could with other water. He could barely even move to swim.

Water had always been a safety net for Percy, but now it felt like it was dragging him down, pulling him into the black of the Styx, never to surface again. It was one of the most frightening things he'd ever felt. As he sank, memories flashed through Percy's mind; his mother and his friends, their faces, smiles, and words of wisdom. Sally, Annabeth, Grover, even Luke.

_"Not giving up already, are you, Jackson?"_ Luke's voice echoed in Percy's mind. The son of Hermes' face came to his mind, a grin tugging at the scar on Luke's cheek. It felt like Percy was back on the training ground, looking up at Luke from where the older demigod had knocked him off his feet. Luke offered him a hand up. "_C'mon. Let's try this again."_

As Percy reached for Luke's hand, he swore he could hear Hestia's voice, echoing distantly; a gentle reminder reaching him from her hearth:

"There is always a Light to guide hearts _away_ from the Darkness."

* * *

Charon had pulled himself out of the Styx, unaffected by its harsh waters. The ferryman, influenced by the Heartless, had regained control of his vessel and had had all intentions of knocking Nico off the grandfather clock that was the son of Hades' lifeboat. Before the boat crashed into the clock, Nico threw himself onto it and was now locked in combat with Charon, his Keyblade deflecting the bone claws that lashed out at him.

Nico was at the disadvantage of being mortal, regardless of his status as a child of Hades; demigods died all the time. Just because Nico was a Keybearer as well didn't mean that he was immortal. Charon, on the other hand, was; he could be defeated, but not killed, not destroyed. At most, Nico could banish the Heartless influence on the ferryman. First, he had to subdue Charon, and that would not be an easy task, even for a him.

With the Heartless influencing him, Charon was strong, fast, and unpredictable. There had never been any stories about him being a violent guy; even spirits in the Underworld would say that Charon wasn't a fighter. Charon was more likely to punish spirits by making them wait another century before bringing them across the Styx. The being Nico fought was not Charon; it was the Darkness embodied within him and that Darkness was not going to back down. It was going to take more than force to take him down.

"Charon, stop this!" Nico told the ferryman, holding his Keyblade up against Charon's bone claws. The boat swayed under them, making it difficult for Nico to hold his footing. Charon took advantage of this to push Nico back. "You can't trust the Darkness! It will make all sorts of promises, but take it from me, it will only betray you in the end!"

Charon made a noise, a snarling laugh in the back of his throat. "You'd know all about betrayal, wouldn't you, Nico di Angelo?" He shoved hard, sending Nico falling back, hard, against the railing of the barge. Nico's Keyblade skidded across the deck, leaving him unarmed. Charon stood over him, his claws stretching out and lifting Nico's chin to force the son of Hades to look at him. "You threw away the gifts offered to you when you betrayed your master."

Nico's dark eyes flashed, a red hue lighting them briefly. "He was _not _my master."

Charon's lips curled, a grotesque sight, as his face was half-skull. His other hand came up, claws shortening as they touched Nico's chest, digging in just over his heart and drawing blood. "You play with the idea that you've turned your back on the Darkness, but it will always be there, lurking in your heart."

"Stop it!"

At that moment, the Styx lurched again, throwing itself over the railing of the barge and slamming into Charon and knocking the ferryman back. Nico, surprised, looked over his shoulder to see Percy surfing across the Styx on an ancient legionnaire shield. Somehow, the other Keybearer seemed stronger, holding himself with an air of confidence as he directed the water of the Styx with his Keyblade.

"Nico, get your Keyblade!" Percy shouted over the noise of the rushing water. "You need to release Charon!"

Nico gave a nod and threw himself across the barge, hand closing over the grip of his Keyblade. He got to his feet and swung the Keyblade at Charon, a beam of silver-white light emitting from the sharp tip as he pointed it at Charon, who was trapped in a sphere of water. The light dispersed through the water, hitting the ferryman. Black seeped into the water, swirling around the sphere. Percy waited for a moment, then let the sphere drop, water, ferryman, and bits of thrown away dreams all splashing onto the deck of the barge.

For a long moment, nothing happened. Both Nico and Percy held their Keyblades at the ready, Percy reaching the barge and boarding, letting the Styx settled underneath them. Charon lay sprawled over the deck, soaking wet, and still. His black robes had returned to normal, the bone claws gone. It would seem, at the moment, that Nico had done it and removed the Heartless' influence on Charon, though it felt too early to say just yet.

Finally, Charon moved, a groan escaping him as he forced himself upright. Nico tensed, waiting for any sign that the deity was going to attack again. Gripping his Keyblade tight, the son of Hades took a step forward.

"Charon?"

Charon looked up at Nico, hollow black eyes fixed on the younger demigod, brows furrowed in confusion. "What...what happened? You..." he paused, studying Nico for a moment, "you're supposed to be dead."

"I'm supposed to be a lot of things," Nico replied, stepping forward again. When Charon made no move to attack, the son of Hades approached him casually, offering the fallen deity a hand up. "Releasing my father is one of them. I take it you won't be interfering again?"

"I don't know what you're talking about."

Percy stepped up beside Nico, Keyblade lowered now that the threat seemed to be over. "We're here to free Hades from the Keyhole. You nearly threw us into the Styx."

"Looks like someone _did_ end up in the Styx," Charon retorted, taking a moment to give Percy a look over. He stood up, pulling a pair of tortoise-shell shades out of his robes as they shifted into his usual suit, and slipped the glasses onto his face before addressing the two demigods again. "I don't remember letting you two on my boat. You should know I don't take the living across my river."

Nico gave an exasperated sigh. "Of course. The Heartless influence _would _affect your mind." He lowered his Keyblade now and it vanished, to wait for him to call it for use again. "Percy, if you'd explain things from the beginning."

Percy gave a frown, but began telling Charon what had happened. Nico paid little attention as the older demigod explained what was going on, though. Something had caught his eye when the water had settled and he wandered over to investigate. Laying on the deck on barge, crumpled and soaking wet, was a floppy green hat. It was all too familiar to Nico and his heart clenched as he crouched down to pick it up. He flipped it over in his hands, taking a peek at the tag sewn into the seam inside the hat.

There, scrawled almost illegibly, was his sister's name. _Bianca. _The last time Nico had seen this hat, his sister had been wearing it, just before she'd left. Before she'd died. She must have been taken across the Styx, if her hat had been in the river. She must have discarded it on her way across. Nico clutched her hat in his hands and turned his head to look back towards where he could just see the light from Elysium. He hoped that was where she was; she was Hades' daughter, so wouldn't it stand to say she'd be given Elysium?

He wondered how long it had been since Bianca had died, how long it had been since he'd fallen into the Realm of Darkness. Nico wasn't sure. Wandering in the dark, lost, and with only a sliver of hope to keep his own light burning, it had felt like ages. He'd woken up in the infirmary, surrounded by strangers, and hadn't bothered to ask anyone what year it was. That would have brought about questions he didn't want to answer and his own question would probably go unanswered.

So he hadn't asked. Hestia might have been able to tell him, but he hadn't asked her. He got the impression that it had been a long time since he'd fallen into the Realm of Darkness. Just looking around him, he knew things had changed while he had been lost. It was obvious that time had passed; Nico just wasn't certain how much time.

Part of him didn't want to know, either. He'd already lost his mother and his sister. Knowing how much time he'd lost as well would probably make things worse. Looking to Elysium, Nico thought, if his sister was there, would Bianca know how long it had been? Would she think he was living a good long life or would she be waiting for him?

_I can't join you yet, Bianca,_ he thought, hugging his sister's hat to his chest. _Not until I make up for what I did. If you're waiting for me, you'll have to wait a little longer._

"Nico?" Percy's voice cut into the son of Hades' thoughts and Nico turned to look at the older boy. He noticed Percy looking at the hat and he dropped his arms to his sides, the hat still in hand. Percy gave a confused frown, but didn't ask about it, telling Nico, instead, that Charon had agreed to take them the rest of the way across the Styx.

Charon was good on his word and got them across. The barge lifted from the water as they reached the other side of the Styx and they soon came up to the lobby of the DOA Recording Studio; the same place Percy had come with Grover and Annabeth during his first quest. It was pretty much the same, with the grey walls and carpet, the black furniture, and the podium where Charon would sit and ignore the souls waiting to be taken across the Styx. Even the radio was the same boring easy-listening station that had been playing the last time Percy had been there.

The only difference was that there were no souls to be seen in the lobby.

Charon was immediately furious. His lobby was never empty; even when he decided to lead a group of souls across the Styx, he always left plenty still waiting. "Did you guys let them out?!" he demanded, whirling on the two demigods.

"We came through from Central Park, how could we let them out?" Percy shot back.

"I know you know your way here, Jackson! You could have lead them out and then went around the back way!" Charon paced the length of his lobby in anger for a moment before pulling a Smartphone from the pocket of his suit. He thumbed the screen and brought the phone to his ear, ignoring Percy's further protests to his involvement in the lobby being empty. "Damn it, Thanny, answer your gods-forsaken phone!"

Nico bit down on his lower lip, crossing his arms over his chest as he did so. There was something definitely wrong and it wasn't just that the souls were gone from the lobby. Hestia had talked about Gaea rising and the Olympians being locked away. Was there a connection between the two? While Charon tried again to get a hold of Thanatos, Nico stepped closer to Percy, grabbing his arm to get his attention.

"We need to go," he told the son of Poseidon. "I have a bad feeling and we need to free my father. He'll know what's going on."

Percy frowned, but gave a nod and followed Nico out of the lobby, leaving Charon to vent his frustration by throwing his phone against a wall and cursing loudly. "What do you think happened?" he asked.

"Either someone went out of their way to kidnap a roomful of souls or the dead are returning," Nico replied. He had a very bad feeling about this and, when a son of Hades had a bad feeling about the dead...it just wasn't something to get into. "Come on. Hestia said my father would be at the entrance to the Underworld. This is it; he has to be here somewhere."

The two of them headed through the building, leaving the lobby, and checking various other rooms. Once or twice, little Shadow Heartless jumped out of dark corners at them and, in the halls of the studio, Nico and Percy had to separate for a bit so they'd have room to fight. When the number of Heartless seemed to increase, they were certain they were getting closer. Percy had always found that Heartless seemed to gather around things that he was after, whether they were Keyholes, a Golden Fleece, or an eccentric mortal girl who could see through the Mist. The Heartless, though mindless, seemed drawn to items and people filled with Light.

"This way!" Percy called Nico over to the door that lead down to the basement. He shoved it open as Nico joined him and the two of them made their way down. Percy looked around as they reached the bottom step. "What do you think?"

"I don't know," Nico told him. This was the only other place they could look, still being part of the building. Neither he nor Percy could see anything that was obviously a Keyhole, like the hearth at Camp Half-Blood, but then, who said Keyholes were out in the open?

"Nico, that hat."

Nico raised an eyebrow, not sure why Percy would be bringing up the hat at a time like this. He'd tucked the hat into his pocket, scrunching it up quite a bit to do so. "What about it?"

"It's glowing," Percy pointed out.

Sure enough, when Nico actually looked, Bianca's hat was glowing with a bright silver light. He pulled it out of his pocket and it lifted itself right out of his hands. As they watched, the light around the hat grew brighter until a beam shot out and hit the far wall of the basement. The light on the wall formed the shape of a Keyhole.

"That's it!" Percy exclaimed. He couldn't be more relieved; he'd spent more than enough time in and near the Underworld and was ready to get out of there.

Of course, just because he was ready to go, it didn't mean he was going anywhere. The Heartless chose that moment to attack again, drawn by the light of the Keyhole. Percy called his Keyblade forth and struck out at a group of Shadows that had leapt towards them. He easily dispatched them and a Soldier that came after them.

"Nico, go!" he told the other Keybearer. "Go unlock the Keyhole and get your dad. I'll handle this!"

The group of Heartless seemed rather focused on Percy, Nico noted. He might as well let Percy handle them. Summoning his Keyblade, Nico ran for the far wall and, as he approached, he could see that the wall was decorated with a dark mosaic. Black tiles embedded in the wall formed an image of a man, a bident in hand: Hades, god of the Underworld and Lord of the Dead. Nico's father.

"Nico, hurry!"

With a glance over his shoulder, Nico realized that the number of Heartless were far more than one person could handle. He needed to get the Keyhole unlocked so he could help Percy. Grasping his Keyblade in hand, Nico brought it upwards, pointing the tip of the blade at the mosaic. He concentrated and could soon sense the Keyhole reacting to his Keyblade. Light emanated throughout the basement room and Nico had to close his eyes to keep himself from going blind. There was a click and, a moment later, a low, but commanding voice came forth.

"_What_ are these creatures doing so close to my doors?"

Hades stepped forward, brushing past his son, and casually waved a hand. The Heartless that had remained even after the light from the Keyhole had taken out a good chunk of their brethren were taken out by the fires of the Phlegethon summoned by the god. Percy and Nico were left standing in Hades' presence.

"Father," Nico spoke up. His voice was shaky and he seemed to shrink under his father's gaze. For all the cockiness that Percy had seen in Nico before, the younger demigod was now little more than a kid facing their parent. "We've freed you from the Keyhole. Gaea and her giants are rising and - "

"I know very well what's going on," Hades interrupted, raising his hand for silence. He moved forward, heading up the stairs, gesturing absently over his shoulder for Nico and Percy to follow him. "Don't waste my time telling me what I already know."

Nico shot a glance at Percy, who looked just as annoyed as he'd been with Charon earlier. They followed Hades back up out of the basement, though Percy tried to keep his distance. Hades didn't look back at them while they were walking, though he spoke of what he knew was going on.

"It's just like Gaea to attempt to rise now, while we're fresh from the last war. It's the Gigantomachy all over again." Hades easily dispatched a group of Heartless that tried to leap out as they made their way back to Charon's lobby. "Next, I'll be finding out she's raised her precious Alcyoneus to grate on my nerves as well!"

He shoved the door to Charon's lobby open and stepped through, surveying the scene. Charon, at the sight of the Lord of the Dead, gave a respectful nod. Hades barely acknowledged it, focused as he was on the recent happenings within his realm.

"Are all of them gone?" he asked.

"Not a soul remains, sir," Charon replied. "Thanatos isn't answering his phone, either."

"Then it's as last time." Hades gave an exasperated sigh and turned on his heel, looking to his son. He studied Nico for a long moment, as if only now realizing who had freed him. Nico managed to stand his ground under his father's scrutiny this time, facing his father with determination. "You have quite the journey ahead of you, Nico."

"I'm ready for it," Nico told him. "I have things to make up for."

Percy arched a brow at that; this was news to him. He knew next to nothing about the boy he was journeying with in the first place. What could Nico have to make up for? What were the things that had landed him in the Realm of Darkness to begin with? It seemed that every little thing that Percy found out about Nico raised more questions than it answered. How was he supposed to travel with this boy to open so many Keyholes when he didn't know anything about him?

"Father, what about the souls that have gone missing?" Nico asked, his voice cutting through Percy's thoughts. "What does that mean?"

Hades' dark eyes stared at his son. "It means that monsters and Heartless are not your only enemies anymore," he explained. He moved over to one of the black leather chairs in the lobby and sat down, resting his elbow on the arm of the chair and propping his chin over his knuckles. "When a soul escapes the Underworld, they come back as a shell of the person they used to be. A Nobody."

"Nobody?"

Hades gestured for Nico and Percy to both take a seat. He didn't seem all too pleased about having to explain this, judging by the irate look he gave. This was vital information, though, and without it, there was little to be done. He'd just have to put up with it for now.

"When a person loses their heart to darkness, a Heartless is born, as you know. At the same time, if that person's will is strong enough, their body will take on new life as a Nobody; a being with no heart. The same thing, in most cases, will occur when a soul returns from the Underworld."

"And all the souls in the lobby...?" Percy ventured.

"Every one of them will have become a Nobody," Charon answered. He leaned against his podium with his arms crossed over his chest, his black eyes hidden by the tortoise-shell sunglasses, making his expression difficult to read.

"Yes," Hades sneered, clearly not happy with this development. "And we will be discussing that later, Charon." His tone suggested that it would not be a pleasant discussion for the ferryman. "For now, Nico, Jackson." He turned back to his son and nephew. "Nobodies are, perhaps, some of the more dangerous beings you've encountered. I won't say to be careful, but by all means, don't do anything stupid."

Percy had to bite back a retort; Hades always made him mad – perhaps not as much as Ares did, but close enough. Nico merely nodded, at least grateful for the information. There was seemed to be a bit more, though, something he was sure was being circumnavigated in this discussion.

"Is there anything else?" he asked. "Another Keyhole you can tell us about?"

Hades was silent for a long moment before he stood up and casually brushed himself off, as though sitting on a pristine leather couch had left some invisible dirt on his slacks. The god gestured for Nico to follow him – only Nico. "Jackson, I don't wish to see you in my Underworld again until it's your time to be judged. Wait outside."

Percy opened his mouth to protest, not happy about having to leave and, especially, about being told to wait outside like a misbehaved student being sent out of the classroom. He'd had enough of that during the school year, to be honest. However, he clearly wasn't part of this conversation, despite being a Keybearer and on a journey to unlock the Keyholes to free the Olympians. Whatever Hades had to say, he would not say it where Percy could hear.

So Percy headed outside. The particular part of Los Angeles where the DOA Recording Studios let out hadn't changed much in the last few years since Percy had last been there with Annabeth and Grover. It was still the same unnerving, sprawled out, chaotic street it had been last time. He half-expected to see old Crusty lurking about outside his shop up the block, scouting out customers to try out his beds - "You'll lose your head over these deals!"

Looking up as he stood on the street, Percy realized that he hadn't known how much time had passed in the Underworld; when he and Nico had entered, it had been late afternoon and now, judging from the sun in the sky, it seemed to be the next morning. Across the street, there was a tiny café that looked as shady as just about anything else in the neighborhood, but had signs in the windows that promised good food at a low price. Deciding it was worth it to get something to eat, Percy hurried across.

If he ran into any trouble, he had his Keyblade, after all.

* * *

It took a long time for Nico to come out of the studio. Percy had bought and eaten two rather greasy scones and downed a large hot chocolate before the son of Hades finally came out. From his seat by the window, Percy had been watching for the younger teen and, when he'd finally seen the door to the DOA Recording Studios open, he'd been more than a little surprised that Nico wasn't alone coming out.

With him was a girl, about Nico's age, maybe a little younger. She seemed disoriented, holding onto Nico's arm and looking around with half-lidded eyes. The two of them were an odd pair, one in stark contrast with the other; Nico being pale-skinned and dressed in dark colors, the girl dark skinned and dressed in light colors. Percy pushed his chair back, grabbed the extra scones he'd bought and headed outside to join them.

"Who's this?" Percy asked as he crossed the street again.

Nico held onto the girl, guiding her and helping her walk. "This is my half-sister, Hazel."

Hazel tilted her head up to look at Percy. Her bright amber eyes were a shock to him; he'd never seen eyes that color before and it wasn't uncommon in demigods to have oddly colored eyes. She blinked at him for a moment, as if she wasn't sure what to do or say. Finally, she smiled lightly at him. "Hello."

"Hi," Percy told her. He gave her a smile in return. "My name's Percy."

"We need to take her upstate a bit," Nico told Percy, cutting off the introductions. He looked around, as though keeping an eye out for someone. "I can't shadow the three of us there. We'll need to get a cab or a bus."

"Where are we taking her?" Percy thought it was suspicious. First, Nico comes out of the DOA Recording Studio with Hazel, who didn't seem to understand what was going on, then Nico tells him they have to take Hazel somewhere 'upstate a bit'? "What's going on?"

"I can't tell you yet."

Well, that wasn't going to go over well with Percy at all. He wrinkled his nose and crossed his arms over his chest. "Nico, this is ridiculous. You expect me to just help you take this girl some place you won't tell me where, you won't tell me what's going on, and I doubt you've told me the truth about who she is - "

"_Later,_ Percy," Nico cut him off. "Right now, we need to get her where she'll be safe for the time being. I've already lost a sister. I'm not losing another."

Percy was actually taken aback by that statement. That was the first thing he'd learned about Nico's past since meeting the son of Hades. A sister? Was the green hat that had led them to the Keyhole something that had belonged to her? What had happened to her that Nico had lost her? There was so much from that one tidbit of information that just opened things up for more questions.

Nico made it clear, though, from his body language and his intent of getting Hazel away from there, that he wasn't about to answer any questions, even ones that pertained to the situation with Hazel. He led Hazel away from the building and headed down the street, holding protectively onto the girl.

"Where are we going?" Hazel asked, her voice soft and confused. She seemed to be quickly picking up on her surroundings, looking around herself with her eyes slowly widening in awe. Her arms were still wrapped around Nico's arm, holding onto him like a life-line.

Nico gave one of Hazel's hands a gentle squeeze in an uncharacteristic show of reassurance. "We're taking you to Camp Jupiter," he told her.

Percy stopped in his tracks, overhearing Nico from where he'd been walking a few steps behind the two siblings. Camp Jupiter? He'd never heard of such a place. Throughout his time at Camp Half-Blood, he'd been told that the camp was the only safe place for demigods. If Hazel was Nico's half-sister, then didn't it stand to reason that she was a demigod and should be at Camp Half-Blood? Nico had distinctly said Camp _Jupiter._

Not for the first time, Percy had the feeling that there was a lot he had to learn about Nico, and now, about Hazel. He started after them again, picking up the pace to catch up with them.

* * *

**End note: **I promise, there is a reason why I'm writing Hazel this way. I'm not trying to write her badly, but this behavior will be explained next chapter! Thank you for being patient with me, as I said in my beginning notes, I am still figuring a few things out, which is making writing the chapters slow. Please send in reviews and let me know what you think!


End file.
